Saudi Arabia and Iran and how we got here

Iranian demonstrators hold anti-Saudi placards in a rally to protest the execution by Saudi Arabia of Sheikh Nimr al-Nimr [AP]

The decision by the Kingdom of Saudi Arabia to recall its diplomats from Tehran and expel all Iranian diplomats is a deeply worrying development in a troubled relationship between the Middle East's pre-eminent regional powers.

The Islamic Republic of Iran has developed a habit of disregarding the 1961 Vienna Convention on diplomatic relations when it sees fit. This is not the first time that angry mobs have stormed embassies, a recent example being the United Kingdom's embassy in Tehran in November 2011.

In response to the attack, the UK closed its embassy and ordered the Iranian embassy in London closed. As such, there is nothing altogether unusual in the Saudi response, which is certainly not unprecedented and outside the usual norms of inter-state relations.

Analysis: Saudi Arabia and Iran relations at its lowest point

Make no mistake though, the diplomatic furore surrounding Saudi Arabia's decision to execute Sheikh Nimr al-Nimr - a Shia Saudi religious leader who had long opposed the Saudi regime - is about tensions that have been simmering between the two sides for years.

Saudi and Iran in a greater game

Nimr has become a pawn in a much greater game - a game which he himself would have resisted being part of were he still alive. His now infamous speech of October 7, 2011 in which he rejected all external interference in his community was directed as much at Iran's leader Ayatollah Khamenei as it was the Al Saud.

That the region's two most powerful countries have ended their diplomatic ties because of his death is ironic to say the least.

Nimr's friendship circles were certainly not comprised of peace-loving pacifists. His clerical inspiration came from the hard-line, politically active Iraqi Ayatollah Muhammad al Hussaini al-Shirazi, who held deep longstanding ties to unpalatable elements in Iran.

The tensions between Iran and Saudi Arabia have reached the point where nuances are quickly abandoned and all actions are interpreted as political.

Moreover, Nimr's notable supporters included Abd al-Raouf al-Shayeb, a Bahraini recently convicted in Britain for possession of materials and information that could aid terrorist activities.

By executing him alongside a number of infamous al-Qaeda terrorists, Saudi Arabia sought to draw equivalence between Nimr and al-Qaeda, arguing that terrorism is terrorism, regardless of creed.

But in today's Middle East that was never going to be enough to calm the waves of anger that erupted across the Shia world in response.

The tensions between Iran and Saudi Arabia have reached the point where nuances are quickly abandoned and all actions are interpreted as political.

Understanding why Nimr's death has so quickly escalated into a diplomatic rift requires understanding why Saudi-Iranian relations have become so tense in recent years.

It is fashionable for people to hark back to the martyrdom of the Prophet's Grandson Hussain at Karbala on the 10th Muharram as a sign that this split between Sunni and Shia has always existed.

An image of Sheik Nimr al-Nimr [AP]

But that is not quite true - sectarianism is a phenomenon that waxes and wanes over time. This current period of tensions stretches back to about 1978, when the first uprisings in the Shia-dominated Eastern Province of Saudi Arabia began against the Al Saud, which were then capitalised upon by the Iranian Ayatollahs after they swept to power in 1979.

Saudi Arabia, Iran and sectarianism

The drivers of sectarianism are rarely only religious, and usually come packaged with cultural disputes, and reams of political analysis about the other side's brutality and oppressive behaviour.

The most recent phenomenon, of course, has been for media personalities on both sides to accuse the other of being the patron of the Islamic State of Iraq and the Levant (ISIL). A cheap political tactic wrapped in conspiracy and with little basis in fact, but which nevertheless resonates deeply across the region, and serves only to deepen the sectarian divide.

As bilateral ties between the two sides are now broken, the only avenue for them to sit and discuss their points of view are via multilateral initiatives.

The spat, therefore, has wider regional implications. As bilateral ties between the two sides are now broken, the only avenue for them to sit and discuss their points of view are via multilateral initiatives.

The Vienna Process and resulting peace talks over Syria and discussions concerning the ongoing conflict in Yemen are now the only places where the two nations can sit together.

However, it is unlikely that any serious rapprochement can be made through these channels. Iran and Saudi Arabia are deeply at odds with each other over both conflicts and the future does not bode well for the already stunted and stumbling diplomatic processes.

Those wishing to bring an end to years of war across the region will have their work cut out for them.

While insecurity across the region is likely to continue and even increase, security in the Gulf itself can be managed. US, British and French military power ensures that direct war will not break out, and these countries will not quickly abandon their Gulf allies.

Notwithstanding this, quite how they will manage a larger rapprochement with Iran following the Iranian nuclear deal is going to be difficult in the coming months. The five smaller Gulf states will have to watch the situation very closely.

Saudi Arabia and its allies

For three decades, they have managed to balance their identity as Gulf Cooperation Council members with their vital economic interests and historical trade relationships to Iran. But the Iran-Saudi break is a real test.

While Bahrain associates itself closely with Saudi foreign policy initiatives and very quickly severed its ties with Tehran, Qatar, UAE and Kuwait did not follow suit.

The UAE has downgraded its relationship with Iran but will not sever it, and it is likely that Qatar will consider something similar. While on Tuesday Kuwait recalled its ambassador, permanently severing relations with Tehran is too damaging for the Gulf states to consider at the current time.

Oman on the other hand faces an even greater conundrum. Often seen as Iran’s only true ally on the Arabian Peninsula, Muscat cannot afford to upset its ties with either Riyadh or Tehran, and it is likely that the Omanis will remain silent for the time being, remaining in full diplomatic contact with Iran while saying nothing against any other Gulf state's decision to cut ties.

Moving forward, the United States and Britain in particular will show a far more visible presence in the Gulf in support of the GCC.

Military exercises are the modus operandi at times of regional tension, and if the Americans want tensions to cool they will need to remind both sides of the Gulf who the real boss is. The problem is that it is US retrenchment from the region that has been the cause of regional competition in the first place, and the Obama administration appears unwilling to do what is necessary to keep the peace.

This is deeply troubling for the region, because without a true security actor to keep Tehran and Riyadh from quarrelling further, the only result will be more insecurity, more competition, and yes, more sectarianism. 2016 looks to set to be another bumpy ride.

Michael Stephens is a research fellow for Middle East studies and head of the Royal United Services Institute in Qatar.

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.